updating radio buttons programmatically

mzimmers

Hi all -

A couple months ago, I implemented a model/view based app. I need to add a pair of radio buttons to the widget. These buttons must be under programmatic control; that is, my worker object needs to be able to change the selected button without user intervention.

I have a row in my model representing the desired selection of the buttons. What I'm not clear on is how to map this column in the model to the UI. Can someone provide some guidance?

Thanks...

SGaist

Hi,

Can you explain the relation between you worker, model and UI ?

It’s not very clear when your button should be modified.

Pablo J. Rogina

@mzimmers a screenshot of your current UI may help a lot as well.

mzimmers

Hey guys -

Here's what I'm trying to do:

This dialog enables a user to review and change configuration details. (There's a "save" and a "cancel" button as well.) But, I need to pre-populate this dialog with the current configuration details (like which IP assignment method is in use).

My target device passes an XML message to my (Qt based) host. A worker thread receives and parses the message, and updates the model via a signal. For all my text-based widgets, I use a mapper call:

    m_mapper->addMapping(ui->ipAddress, TAG_IPV4ADDRESS);

But I don't know how to do this for a radio button.

Pablo J. Rogina

@mzimmers assuming that you have a QButtonGroup for the "IP Address Assignment" I guess you may want to take a look at this capability from such widget:

In addition, QButtonGroup can map between integers and buttons. You can assign an integer id to a button with setId(), and retrieve it with id(). The id of the currently checked button is available with checkedId(), and there is an overloaded signal buttonClicked() which emits the id of the button. The id -1 is reserved by QButtonGroup to mean "no such button". The purpose of the mapping mechanism is to simplify the representation of enum values in a user interface.

SGaist

What you can do is create a custom widget for your address type widget and add a property to it and in the setter you activate the correct button based on the text passed.

mzimmers

OK, this is helpful. I've added the following to my model update routine:

    // the IP configuration source.
    s = msg->getValue(msgTag[TAG_IP_CONFIG_SRC]);
    if (s == IP_SOURCE_TXT[IP_SOURCE_DHCP])
    {
        m_model->setData(m_model->index(row, TAG_IP_CONFIG_SRC), IP_SOURCE_DHCP);
    }
    else
    {
        m_model->setData(m_model->index(row, TAG_IP_CONFIG_SRC), IP_SOURCE_STATIC);
    }

And the following in the c'tor of my dialog:

   QButtonGroup *m_qbg;    // button group for IP source selection.
     ...
    m_qbg->addButton(ui->ipDhcp);
    m_qbg->setId(ui->ipDhcp, IP_SOURCE_DHCP);
    m_qbg->addButton(ui->ipStatic);
    m_qbg->setId(ui->ipStatic, IP_SOURCE_STATIC);

Do I need to read the model data, and manually change the appropriate button's checked status? I can do this, but...I don't know where I'd put that code. A slot to accept the buttonChecked() signal would work for user-initiated changes, but I don't think that will work for programmatic changes, will it?

Pablo J. Rogina

@mzimmers said in updating radio buttons programmatically:

but I don't think that will work for programmatic changes,

Where are you parsing the XML data sent by the device(s)?

I guess that wherever you are setting the IP address/netmask/etc you can set the IP mode, i.e.

foreach (QAbstractButton* button, n_qbg->buttons())
{
    if (id(button) == <ID_VALUE_FROM_XML_EITHER_DHCP-ID_OR_STATIC-ID>) {
        button->setChecked(true);
        break;
    }
}

mzimmers

@Pablo-J.-Rogina The worker receives the XML message and passes it to the object that contains the model. For each field, I have a bit of code like this:

    // the IP address.
    qs = QString::fromStdString(msg->getValue(msgTag[TAG_IPV4ADDRESS]));
    m_model->setData(m_model->index(row, TAG_IPV4ADDRESS), qs);

I can set model data from here, but I don't have direct access to dialog widgets.

Pablo J. Rogina

@mzimmers said in updating radio buttons programmatically:

but I don't have direct access to dialog widgets.

But at some point data from the model is used to update the dialog widgets?
If not, how the IP address value is taken from?
If so, what about adding the IP address mode (DHCP/Static) field to your existing model?

mzimmers

I use a QDataWidgetMapper object in my dialog to access the fields.

    m_mapper->addMapping(ui->ipAddress, TAG_IPV4ADDRESS);

This maps a line edit to a column in my model. But I don't think I can simply do the same thing for a button group.

EDIT: by the way, I don't have to use radio buttons for this. They seemed like a good choice, but if there's a better method, I'm happy to entertain ideas.

Pablo J. Rogina

@mzimmers said in updating radio buttons programmatically:

I use a QDataWidgetMapper object in my dialog

having stated this from the very beginning should have saved time and effort, and allow us to narrow down the issue... :-)

Given that said, maybe this post may help

mzimmers

@Pablo-J.-Rogina said in updating radio buttons programmatically:

@mzimmers said in updating radio buttons programmatically:

I use a QDataWidgetMapper object in my dialog

having stated this from the very beginning should have saved time and effort, and allow us to narrow down the issue... :-)

Sorry -- I thought I had done so here:
https://forum.qt.io/topic/93723/updating-radio-buttons-programmatically/4

In any event, it may be time to consider a different approach.

SGaist: looking at your response, I have a couple questions:

you mention customizing my address type widget - are you referring to the buttongroup?
What do you mean by "the setter"?

SGaist

I mean make a custom widget e.g.:

class IpAddressTypeWidget : public Widget
{
    Q_OBJECT
    Q_PROPERTY(QString addressType GET addressType SET setAddressType NOTIFY addressTypeChanged USER true)

public:
    explicit IpAddressTypeWidget(QWidget *parent=nullptr);

    QString addressType() const;

signals:
    void addressTypeChanged(const QString& type);

public slots:
    void setAddressType(const QString& type);
};

In setAddressType, you update the radio buttons based on the string given. Note that you can also use an enum and it's the role of the parser to use the correct enum when changing the address type. It would be cleaner but for a first round, it might be easier to use a QString.

mzimmers

OK, I think I understand what you're suggesting, but some of the mechanics still aren't clear to me.

Does this new widget replace any of my existing widgets, or does it just exist (invisibly) within my dialog?

Do I need to pass it my ui pointer at construction to give it access to the rest of the widgets?

SGaist

It's an independent widget where you put your QGroupBox which contains the two QRadioButton.

mzimmers

I'm still wading through this, but I did discover a necessary change in the Q_PROPERTY macro:

    Q_PROPERTY(QString ipSource READ ipSource WRITE SetIpSource NOTIFY ipSourceChanged USER true)

It wouldn't compile with the GET/SET terms.

mzimmers

SGaist: in your example above, where does the signal come from that connects to the slot setAddressType()?

SGaist

IIRC, you are using a QDataWidgetMapper for that editor ? Correct, then with that definition, when you call addMapping it will use that property to get and set the data from that widget in the same manner as it does for QLineEdit or QSpinBox.

mzimmers

OK, I think I get this in principle. From an implementation standpoint, how/when should the edit dialog retrieve this information from the custom widget -- another signal/slot?

Thanks...